I need a good android app for me to make money..

Hi guys , im looking for those who have a very creative ideas on an android app so i can make some money by selling my service on this applications.. The service will be any kind of application. Please propose it to me.. Whether is a games app, gambling app, information app, greeting card app or etc. My budget is arround USD 250 below..maybe we can discuss much higher if i find that the app is really great to get it.. please offer me your best idea, and provide me a screenshot with description of your applications.. thank you very much..